Staphylococcus epidermidis Colonization Is Highly Clonal Across US Cardiac Centers

Background. Little is known about the clonality of Staphylococcus epidermidis in the United States, although it is the predominant pathogen in infections involving prosthetic materials, including ventricular assist devices (VADs). Methods. Seventy-five VAD recipients at 4 geographically diverse US cardiac centers were prospectively followed up to 1 year of VAD support. The anterior nares, sternum, and (future) driveline exit site were cultured for S. epidermidis before VAD insertion and at 7 times after surgery. Infection isolates were also collected. Isolates were typed by pulsed-field gel electrophoresis. A subset underwent susceptibility testing and staphylococcal chromosomal cassette mec and multilocus sequence typing. Results. A total of 1559 cultures yielded 565 S. epidermidis isolates; 254 of 548 typed isolates (46%) belonged to 1 of 7 clonal types as defined by pulsed-field gel electrophoresis. These clones were identified in up to 27 people distributed across all 4 cardiac centers. They caused 3 of 6 VAD-related infections. Disseminated clones were more antibiotic resistant than were less prevalent isolates (eg, 79% vs 54% methicillin resistant; P = .0021). Conclusions. This study revealed that healthcare–associated S. epidermidis infection is remarkably clonal. We describe S. epidermidis clones that are highly resistant to antibiotics distributed across US cardiac centers. These clones may have determinants that enhance transmissibility, persistence, or invasiveness. Clinical Trials Registration. NCT01471795

Relation of Physician Specialty and HIV/AIDS Experience to Choice of Guideline-Recommended Antiretroviral Therapy

BACKGROUND: Controversy exists regarding who should provide care for those with HIV/AIDS. While previous studies have found an association between physician HIV experience and patient outcomes, less is known about the relationship of physician specialty to HIV/AIDS outcomes or quality of care. OBJECTIVE: To examine the relationship between choice of appropriate antiretroviral therapy (ART) to physician specialty and HIV/AIDS experience. DESIGN: Self-administered physician survey. PARTICIPANTS: Random sample of 2,478 internal medicine (IM) and infectious disease (ID) physicians. MEASUREMENTS: Choice of guideline-recommended ART. RESULTS: Two patients with HIV disease, differing only by CD4+ count and HIV RNA load, were presented. Respondents were asked whether ART was indicated, and if so, what ART regimen they would choose. Respondents' ART choices were categorized as “recommended” or not by Department of Health and Human Services guidelines. Respondents' HIV/AIDS experience was categorized as moderate to high (MOD/HI) or none to low (NO/LO). For Case 1, 72.9% of responding physicians chose recommended ART. Recommended ART was more likely (P < .01) to be chosen by ID physicians (88.2%) than by IM physicians (57.1%). Physicians with MOD/HI experience were also more likely (P < .01) to choose recommended ART than those with NO/LO experience. Finally, choice of ART was examined using logistic regression: specialty and HIV experience were found to be independent predictors of choosing recommended ART (for ID physicians, odds ratio [OR], 4.66; 95% confidence interval [95% CI], 3.15 to 6.90; and for MOD/HI experience, OR, 2.05; 95% CI, 1.33 to 3.16). Results for Case 2 were similar. When the analysis was repeated excluding physicians who indicated they would refer the HIV “patient,” specialty and HIV experience were not significant predictors of choosing recommended ART. CONCLUSIONS: Guideline-recommended ART appears to be less likely to be chosen by generalists and physicians with less HIV/AIDS experience, although many of these physicians report they would refer these patients in clinical practice. These results lend support to current recommendations for routine expert consultant input in the management of those with HIV/AIDS

Process stability of Capsicum annuum pectin methylesterase in model systems, pepper puree and intact pepper tissue

Process stability studies towards temperature and/or pressure on pepper pectin methylesterase (PME) were carried out in different systems (purified form, crude extract, pepper pieces and puree) at pH 5.6. Within the temperature range studied (22–80 °C, 5 min), pepper PME in pure form and crude extract was gradually inactivated showing a biphasic inactivation behaviour, indicating the presence of isoenzymes of different thermostability. Pepper samples heated for 15 min showed a maximum of residual PME activity around 55 °C. Isothermal inactivation of pepper PME in purified form and crude extract at pH 5.6 could be described by a biphasic inactivation model for the temperature range studied (62–76 °C). A stable behaviour towards high-pressure/temperature treatments (400–800 MPa/25–60 °C) was observed for crude extract and purified pepper PME. PME in pepper puree samples revealed to be very pressure stable. Mild temperatures combined with pressure treatments seem to increase the extractability from PME in pepper tissue, probably due to the effect on the cell structure